eziosoft

I thought servo.read() only returned what angle you'd set it to - the servo doesn't have any way of returning it's actual physical position. Or am I wrong?

Andrew

yes you are right. I've used servo.read() to not create other variables and save some ram. There is no feedback form servos. The program sends position and then wait for a moment. Servos are quite fast and the program sends values which are +-1 degree compare to the last position so it takes very small amount of time to set the servos on the right position.

I'm confused as well. Can you kindly explain again from where do you get the measurement of the servo angle...when it doesn't have any feedback.

for calibration I've measured angles manually.

new link: http://www.ezio.ovh.org/pliki/arm_plotter_v2.rar

P.S.you can have the feedback from servos if you connect potentiometer from servo to the arduino's analog pin, but I haven't tried this.

I made a 2 axis plotter from the chassis of a broken Roland plotter, just used the motors and mechanism, but my software is very crude. ( it was my first attempt at programming )

I have two steppers, and a pen up solenoid ( to actually move a nozzle up - its a machine for doming with urethane.)

I can set a pattern in the arduino and let it run, but I have to reprogram each time I have to dome another shape label.It would be nice to have it connected to a pc and just call up the right shape from a file.

45 years of editing projects with a knife and soldering iron, then I found Arduino !

Thanks Eziosoft for sharing your project. I am trying to put together something very similar where precision is critical. However I am a complete newbie. I'll appreciate if anyone can provide brief feedback on the following:

1. I plan to use three Hitec HS55 servos for the arms and the pen. Is this a good enough servo for high precision?2. Is the Arduino Uno the right chip for this project?3. Do you know if there is any code similar to Ezisoft's in C#? I am more familiar with C# and hope to build upon it for further functionality.

Thanks for the feedback. To give you an idea, I am trying to make sure my plotter writes reasonably well on college-ruled-lines paper (7mm spacing). The two arms are 6" long each. Can you please suggest a servo (reasonably priced, may be <$30) that would do this job and work with the Arduino Uno? The servo rotation would have to be 180 deg.